Miniaturization is a growing trend for bioanalytical instruments. Integration of sensing, detection, and manipulation functionalities in a small space promises a new generation of inexpensive, portable and highly sensitive equipment that can benefit public health in many, possibly disruptive ways such as point-of-care devices in homes and medical practices or as rugged detectors for prevalent infectious diseases in underdeveloped countries. The long-term goals of our research are, therefore, to develop a new generation of optofluidic instruments in which both microfluidic and optical components are integrated in the plane of a single chip, thus allowing for smaller, less expensive, and more robust instruments. In addition, these instruments should possess exquisite sensitivity on the single-particle level. In this application, the development and characterization of integrated optical particle traps for all-optical manipulation of particles on a chip is proposed. Trapping and manipulation of bioparticles with light using optical tweezers has already led to a dramatic increase in our understanding of cells and molecules. The translation of these capabilities to a chip using integrated optics in lieu of high-end microscopes will enable their application to disease detection and other public health issues. The proposed research has two specific aims: Aim 1: A new type of integrated optical particle trap will be introduced and characterized. A trapping principle based on intrinsic properties of integrated waveguides will be implemented in liquid-core ARROW waveguides as the model optofluidic platform. The relevant trap properties such as trap strength and unique features that take advantage of its integrated nature will be characterized using inorganic microspheres as test particles. These studies will be complemented by analytical and numeric modeling. Aim 2: New bio-analytical capabilities on a chip using optical particle control will be demonstrated. Functional capabilities including particle concentration, single particle fluorescence, optically controlled particle binding and reactions in microenvironments will be demonstrated using representative biological particles including liposomes, E.coli bacteria, and DNA molecules. This will be achieved through the combination of the new trap properties with established techniques for waveguide design and fabrication, and sensitive optical detection. At the end of this project, all-optical particle control using integrated waveguides will have been firmly established as a new tool in optofluidics and major step towards next generation bio- analysis on a chip.